speedometer

BMWX52000 · Posted at Wed Sep 19, 2007 6:52 pm

Hi, I started my car in the morning and couple seconds after that, the ABS, BRAKE, traction control light�s went ON and when I started driving the car I noticed the speedometer was not working, i had one of my friends look at it and hook it up to a computer and he said he couldn't find any faults and the main computer was geting the speed from the speed sensor (we were driving the car with the computer hooked up to the car)any idea what�s wrong ( I checked all the fuses and they are all o.k.)

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2CarPro Ken · Posted at Wed Sep 19, 2007 7:13 pm

it sounds like the vehicle speed sensor is out and needs to be replaced. It should be in the transmission or rear end.

Dr. Hagerty · Posted at Thu Sep 20, 2007 8:26 am

BMW uses the signals from the wheel speed sensors to determine indicated speed.
This all goes through the anti-lock braking system that BMW calls DSC or dynamic stability control.
If you do not get an indicated speed at the cluster you may need to have the vehicle scanned with proprietary software as some of the generic scanners do not or can not "see" the problem.
But try this first, access the battery under the spare tire, and disconnect the negative side from the battery for 10 minutes. This is what BMW calls a master battery reset and can help diagnose many software related issues.
If this helps, it may indicate the need to replace the instrument cluster or it could be just a software glitch.

2CarPro Ken · Posted at Thu Sep 20, 2007 11:04 am

good call, on chevys its all done by the VSS. thats bmw taking it to the next level for ya... thanks for the input Dr.